Method and machine for strapping boxes



Feb. 3, 1942. w, U' W 2,271,596

METHOD AND MACHINE FOR. STRAPPING BOXES Filed May 51, 1940 2 Sheets-Sheet 1 gig; I.

VV/LL/AM H. 1/66/11/5 INVENTOR BY ym ATTORNEY Feb. 3, 1942. 'w. H. LI GGINS METHOD AND MACHINE FOR STRAPPING BOXES Filed May 31, 1940 2 Sheets-Sheet 2 VV/LLl/IM H. A mews INVENTOR ATTORNEY Patented Feb. 3, 1942 METHOD AND MACHINE FOR STRAPPING BOXES William Harry Liggins, Los Angeles, Calif., assignor to Harbor Box & Lumber (30., Los Angeles, Calif., a corporation of California Application May 31, 1940, Serial No. 338,187

7 Claims.

This invention pertains to improved methods and devices for applying a protective binding, strengthening and finishing strap or tape to'the edge portions of boxes, crates and the like, and is particularly directed to an attachment capable of being placed on standard forms of existing nailing machines whereby the application of the metal strap or tape is facilitated.

Heretofore machines for applying strips of metal tape or strapping to edge portions of Wooden boxes, crates and the like, either before or after the same had been filled, involved jigs, clamps and other devices for grasping the tape and tensioning the same during the nailing operation, and such devices and. methods involved complicated machines and often impaired or injured the metal strap or tape by roughening the same and nicking it. Scratches, nicks and the like formed in the tape very often cause minor injuries to persons handling the crates or boxes and furthermore expose the underlying metal and facilitate corrosion at such points.

It has been thought necessary heretofore to apply positive tension to the metal tape or strap during its application for the purpose of assuring close adherence of the tape to the corners of the box. In accordance with the present invention, however, the metal strap is not subjected to a tension applied by the use of gripping tools or jaws but instead close adherence of the strap to the corners of the box and positive positioning of the strap is attained by pressing and forming the strap at the corner portions of the box in timed relation with the nailing operation.

In thismanner, the strap is positively held at the corner of the box and embedded in the cor-' formed without in any way injuring, defacing or roughening the strap or tape.

An object of the present invention, therefore, is to provide a simple, inexpensive method of fitting metal straps, tapes, or the like onto the edge portions of boxes, crates, and other containers.

A further object of the invention is to provide an inexpensive simple attachment for use on standard nailing machines for the purpose of facilitating the application of metal straps and tapes to portions of a box or other container.

Another object is to provide means for applying and forming a metal strap'or tape to a box, crate or other container whereby an ordinary nailing machine may be converted into a combined nailer and strapper.

These and other objects will be apparent to those skilled in the art from the following deof the machine showing the attachment.

Fig.4 is a side elevation of Fig. 3.

Fig. '5 is a horizontal section taken along the plane V-V of Fig. 3.

Fig. 6 is a horizontal section taken along the plane VI-VI of Fig. 3.

Fig. 7 is an enlarged View of a corner of a box carrying a metal strap applied in accordance with the method of this invention.

It is not necessary to describe in detail a complete nailing machine since automatic nailing machines are well known in the art. Suffice it to say that a nailing machine of the character shown in Fig. 1 includes a frame, generally indicated at I0, a vertically adjustable table II, a nail pan I2, a nail feed, indicated at l3, and adjustably positionable nail chucks, generally shown at M. Suitable driving mechanism is embodied in the machine, the actual nail-driving operation involving the vertical reciprocating movement of a driver beam [5 and correlated elements, the driver beam being placed in operation by means of a clutch controlled by a treadle l6. Suitable stop gages are also provided on a nailing machine of this character, a backstop gage being indicated at I! (best shown in Figs. 3 and 6), and one or more side stops, such as the stopl8 shown in Fig. 1. These side stops maybe attached to the table II at any desired point or they may be attached directly to the frame l3.

When the attachment of this invention is made a part of a normal'nailing machine, the operations of forming a strapped box include first nail-' ing the ordinary framing and bottoming so as to formthe' box, and then applying the strap or tape to the box. Ordinarily a number of nailing machines are used, one machine performing the bottoming operation whereas other machines apthe straps are precut to a desired length. If, for example, the strap is to completely encircle the :end portion of a box, the-strap is firstprecut-to' a .through the boss 27.

nailed along another side of the box. The feeding and forming shoes of the device of this invention form the corners on the strap and fit the strap at such corners to the box.

This general operation will be readily understood by considering the device itself, which is indicated generally at in Fig. 1. As shown in Figs. 3, 4, 5 and 6, an auxiliary frame, indicated at 2 I, is attached to the main frame It] by means of the machine screws 22 and 23. This auxiliary frame is at approximately the level of the nail chucks Hi. The frame 2| may be provided with guides adapted to receive a shoe carrier 24. Re-

tainers 25 and 28 may be carried by the auxiliary I frame 2| so as to form guides capable ofreceiving and movably holding the shoe carrier 24. The shoe carrier 24 is provided with a boss 21 extending through an opening 28 formed in the auxiliary frame 2| and a roller or encased roller bearing 29 is mounted upon a stud 30 extending This roller 29 cooperates with a slotted cam arm 3! provided with a cam slot 32, the cam arm 3| being attached to the driver beam l5 of the nailing machine, as indicated at 33. The cam arm 3| may also carry an L-shaped member 34 adapted to cooperate with the frame It so, as to slidably move along said frame. Vertical motion of the driver beam and slotted cam arm 3! will therefore produce horizontal reciprocating motion of the shoe carrier 24 within the auxiliary frame 2|.

The shoe carrier 2| carries an adjustable fitting and forming shoe 35. Any means of adjustably holding the fitting shoe upon the carrier may be employed but for purposes of illustration, the fitting shoe is shown provided with a slot 36, machine screws 3?. and 38 extending throughsuch slot and holding the shoe in position.

The fitting and forming shoe is provided with a concave face 39 adapted to form and fit the metal strap or tape onto the corner of the box. f

By referring to Fig. 3, it will be seen that before the strap 49 is actually nailed onto the box, the strap is slightly bent and caused to overlie the upper edge area of the box. The strap, however, does not closely fit the corner. Immediately prior to the driving of the nails through the strap the downward movement of the driver beam I5 and of the slotted cam arm 3| forcibly moves the shoe carrier 24 and the fitting and forming shoe 35 against the corner of the box, causing the strap to the partly embedded into the corner of the box and thereby permitting the strap 40 to be nailed in an extended, closely adjacent position. At the conclusion of the nailing operation just described, the strap 40 adheres to the corner as shown in Fig. 7. In Fig. 3 the downwardly extending portion of the strap 40 may comprise the end of the strap and if the nailing machine is provided with only one device of the character described, positioned at the left hand side of the machine as shown in Fig. 3, then at the conclusion of the operation just described the box may be turned over on its side (with the previously nailed side in a vertical position and on the left, in terms of Fig. 3) and the strap then nailed onto another side of the box. When the strap is being nailed to the second or third side of the box, the forming shoe presses and extends the strap toward the free end of the strap from the previously nailed side. ,After the strap has been nailed to the three sides of the box, the loose ends of the strap may be nailed by hand or if desired, the box may then be inserted into a machine provided with two devices of this invention, one on each side, and the loose ends firmly nailed down in overlapping relation.

7 It will be obvious to those skilled in-the art that the precise sequence of strap nailing operations may be varied, depending upon the number of machines equipped with the improvements of this invention, the type of box or crate which is being reinforced and treated, and the number of attachments carried by each of the nailing machines used in the plant or operation.

Attention is called to the fact that the movement of the forming shoe 35 against the strap or metal tape in the corner region of the box or crate causes the wood at such corner and beneath said strap or tape to be compressed and when the forming shoe or shoes move outwardly so as to,v disengage, the wood tends to expand, thereby placing the tape or strap under some tension. I In this manner, the wood of the box itself is utilized in maintaining the strap in close positive adherence to the box. The amount of pressure exerted by the forming shoes upon the box may be readily adjusted and modified by adjustably positioning the shoe upon its carrier. 2|. 'The cam slot 32 of the slotted cam arm 3f is so arranged as to mantain the forming shoe in pressure contact with the wood until the nailing operation is completed and the length of dwell can be controlledv by varying the shape ing within the scope of the appended claims are embraced thereby.

I claim: a

1. In a nailing machine including a frame, a table, a nail hopper, nail chucks, a driver beam and means for reciprocating the driver beam, the combination of an auxiliary frame provided with guides and attached to the frame of the nailing machine at the level of the nail chucks; a shoe carrier'reciprocably movable horizontally in said guides of said auxiliary frame; a fitting shoe adjustably held by said carrier; and a slotted cam arm attached to the driver beam and movable therewith and operably connected to said shoe carrier to move said fitting shoe into forcible con- .tact with the corner portion of a strap being in said guidesof said auxiliary frame; a fitting shoe adjustably held by said carrier in virtual .alignment with the bottom ofsaid nail chucks,

said shoe being provided with a concave face portion; and a slotted cam arm attached to the driver beam and movable therewith and operably connected to said shoe carrier to move said fitting shoe into forcible contact with the corner portion of a strap being nailed on a box.

3. In a nailing machine including a frame, a table, a nail hopper, nail chucks, a driver beam and means for reciprocating the driver beam, the combination of: an auxiliary frame provided with guides and attached to the frame of the nailing machine at the level of the nail chucks; a shoe carrier reciprocably movable horizontally in said guides of said auxiliary frame; a fitting shoe adjustably held by said carrier; and an apertured cam arm attached to the driver beam and movable therewith and operably con-- nected to said shoe carrier to move said fitting shoe into forcible contact with the corner portion of a strap being nailed on a box slightly in advance of the nailing operation and to maintain such contact during the nailing operation.

4. In a nailing machine including a frame, a table, a nail hopper, nail chucks, a driver beam and means for reciprocating the driver beam, the combination of: an auxiliary frame provided with guides and attached to the frame of the nailing machine at the level of the nail chucks; a shoe carrier reciprocably movable horizontally in said guides of said auxiliary frame; a fitting shoe adjustably held by said carrier, said shoe being provided with a concave face portion; and a slotted cam arm attached to the driver beam and movable therewith and operably connected to said shoe carrier to move said fitting shoe into forcible contact with the corner portion of a strap being nailed on a box slightly in advance of the nailing operation.

5. In a nailing machine including a frame, a table, a nail hopper, nail chucks, a driver beam and means for reciprocating the driver means, the combination of: an auxililary frame provided with guides and attached to the frame of the nailing machine at the level of the nail chucks; a shoe carrier reciprocably movable horizontally in said guides of said auxiliary frame; a fitting shoe adjustably held by said carrier; and means, operably connecting the driver beam and fitting shoe for translating downward motion of the driver beam into horizontal movement of the fitting shoe whereby said fitting shoe is forcibly pressed against the corner portion of a strap being nailed on a box slightly in advance of the nailing operation.

6. In a method of applying a strap to a wooden box or other container, the step of: nailing a portion of a strap to the side surface of a box, placing another portion of the strap on the surface of an adjoining side of the box, moulding the strap around the corner of the box formed by said sides by pressing the strap into the box to compress the wood at such corner without subjecting the unnailed strap portion to tension and nailing the strap to the surface of such adjoining side of the box while pressing the strap into the box corner.

'7. In a method of applying a strap to a wooden box or other container, the steps of nailing a portion of a strap to the side surface of a box, placing another portion of the strap on the surface of an, adjoining side of the box, moulding the strap around the corner of the box formed by said sides by pressing the strap into the box in the direction of the unnailed strap length to compress the Wood at such corner without subjecting the unnailed strap portion to tension and nailing the strap to the surface of such adjoining side of the box while pressing the strap into the box corner whereby subsequent expansion of the wood at such previously compressed corner places the nailed strap under tension.

WILLIAM H. LIGGINS. 

